COMPUTER SYSTEM AND DISK CONTROLLER

摘要

PROBLEM TO BE SOLVED: To reduce the busy frequency of a CU(control unit) when the multiplicity of exchange increases and reaches the limit of processing capability of a DKC(disk controller) in a system where one or more CPUs can be connected to the DCK via a fiber channel. SOLUTION: An exchange queue table 17 registers an exchange under progress, and an exchange queue management table 18 stores the threshold of exchange multiplicity. An ACK-1 frame holding management table 19 manages a held ACK-1. A DKC 6 registers the transmission of the ACK-1 on the table 19 to delay it with respect to a receiving frame when the multiplicity of the exchange under progress exceeds its threshold by referring to both tables 17 and 18.